1. Field of the Invention
The present invention relates to an improved gene splicing method, to recombinant plasmids and to transformed hosts produced therefrom. In particular, the present invention relates to a method whereby the selection of transformed hosts having a particular phenotypic trait is greatly simplified.
2. Prior Art
The basic prior art is described in U.S. Pat. No. 4,237,224 to Cohen and Boyer. The pioneering effort described in this patent provided the starting point for the present invention and is familiar to all those skilled in the art. There is a large body of prior art which is directly related to this patent. The patent terminology is generally used herein.
In my U.S. patent application Ser. No. 147,563 and related foreign applications, I described new plasmid vectors derived from plasmid pRO 1600. These plasmid vectors are used in the present invention. U.S. Pat. No. 4,278,765 to Debabov et al describes other vectors and recombinant plasmids. U.S. Pat. No. 3,813,316 to Chakrabarty describes multiple plasmid containing Pseudomonas and the method for their preparation.
In the method of application Ser. No. 147,563 as in the method of the Cohen and Boyer patent, indirect selection of recombinant plasmids which are transformed into a recipient host is described. This method involves the selection for a marker in the transformed bacteria and the selection for the particular phenotypic trait. The selection method is laborious and time consuming in obtaining a particular phenotypic trait and provides one important reason why genetic research has been expensive. The reason for this result is that the transformation frequencies are low (or non-existent) in relation to a particular gene in a recombinant plasmid.